Ask An Expert
What do I do if the doctor tells me I’m not an excellent candidate for surgery?
Scott Grealish M.D.
Over the past ten years I’ve seen thousands of patients in consultation for Lasik surgery. As any seasoned surgeon realizes, not all patients are ideal candidates for surgery. Analyzing and explaining the risks vs. benefits for a given patient is part science and part the art of medicine. My experience as a surgeon and interaction with my colleagues over the years has led me to formulate some guidelines which I hope will help others in their decision making.
“Garbage in, garbage out”
Many Lasik candidates have a history of wearing contact lenses and therefore may have contact lens induced dry eye and /or contact lens induced warping of the cornea. Both factors often lead to “abnormalities” on our screening tests that can resolve over time by not wearing the contacts and/or treating the dry eye. Since the key tests measuring the shape of the eye rely on an adequate layer of tears coating the surface of the eye, any tear deficiency can give false readings. Many contact lens wearers have lost sensitivity on their corneal surface from years of wearing contacts. They often don’t complain of feeling dry, even when the doctor finds significant signs of dry eye on examination. Before making real conclusions about your eyes, it is often necessary to discontinue contact lenses and treat dry eye for some time before final testing.
How normal is “normal”?
In reality, we now test so many variables to screen for surgery that is becoming “normal” to see one or more tests come out “abnormal”. This is because no single test is perfect. This can get tricky to explain, but is worth understanding. One way to evaluate the quality of a test is called sensitivity. If a test is 90% sensitive, when you test 100 people who have a disease the test will correctly identify 90 of them and miss 10 of them, something we call false negatives. Another way to check test quality is called specificity. If a test is 90% specific, when the test finds 100 people have a disease, 90 of them will actually have it and 10 will be false positives. In the realm of testing for risk before Lasik surgery, the most critical tests involving the shape of the cornea are actually less than 90% sensitive and specific in many cases. Surgeons are rightly more concerned with missing abnormalities, and therefore many of our tests are quite sensitive, but not specific enough, i.e. they read abnormal in too many normal cases where no real disease is present. So in our clinics where we test over 20 variables before surgery, it is in fact to be expected that some of the tests might be read as “abnormal” when in fact the doctor has no reason to think any real disease exists. As our technology for screening patients has expanded, so too has our rate of false diagnosis for potential corneal problems. So why bother with all the latest testing? More tools have allowed us to be more sensitive in our screening so that hopefully we will never miss that rare patient that truly does have a corneal disease and therefore should not have Lasik surgery. The key to sorting out who should proceed with surgery is in the appropriate interpretation of the whole picture by an experienced surgeon.
“All road signs should lead to Rome”
If an abnormality of your cornea is really present and truly poses increased risk, there should be many signs pointing the surgeon to that conclusion. The more isolated the “abnormality”, the more likely it is a false result of testing. However, truly abnormal findings are typically cumulative with multiple tests indicating abnormality, and they are repeatable at different times, consistently pointing to the abnormality. Cumulative, repeatable evidence is the strongest kind in science and should be clearly explained to each patient in detail when making a surgical decision.
“Precisely wrong or roughly correct”
The concept of a precise computerized testing system for evaluating Lasik candidates is naturally appealing to both surgeons and their patients. But “precision” can in fact be misleading. For example, the latest tools for assessing risk prior to Lasik utilize a grading system that incorporates a patient’s age, corneal thickness before and after surgery, prescription, and the shape (topography) of the cornea. Several of these can be measured precisely, age for instance. The corneal thickness (which implies strength or lack thereof) before surgery can be measured exactly, but the corneal thickness afterward is really only a prediction beforehand, and cannot be exactly known until after surgery. The shape of the cornea is determined by the surgeon’s qualitative (i.e. not numerically precise) interpretation of quantitative data (the raw numbers measured by the computer). This lack of precision is not so much a problem as it is a real reflection of the entire process of surgeon interpretation. As an example, consider that in the best current grading system, a 27-year-old with 511-micron corneas has 0 risk points and a 28-year-old with 510-micron corneas has 2 risk points (and is therefore higher “risk”). We can only conclude that the grading system is precisely right and in reality totally wrong. Those patients are likely identical in risk with respect to those two issues. An experienced surgeon would use such a system as a guide only and interpret the risk for a given patient in broader, less precise, but I would argue more “roughly correct” terms. Eye surgeons and their patients rely heavily on the latest technologies to correct vision. Indeed, the precision needed to refocus the eye can only be achieved with the most sophisticated computer guided lasers. When it comes to the decision making before surgery however, the best “computer” is a skilled, experienced, and caring surgeon who takes the time to look at the big picture and guide each patient individually to achieve their goals for their eyes.
“Treat the patient, not the cornea”
It’s hard to describe to a non-surgeon the many intangibles that go into a pre-surgical consultation that help guide an experienced surgeon in their decision making. The risk/benefit equation of any surgery is just that, an equation with three variables: risk, benefit, and the balance (or ratio) of those. Even if we had perfect tools as surgeons to precisely identify risk in every case, we would still be left with the equally important tasks of identifying the unique benefits that each patient would enjoy as well as assessing what balance of risk vs. benefit each patient is willing to accept as part of the surgical experience. This is why we take into account patients visual expectations, occupations, hobbies, age, and prior ocular history as part of the decision making process. Perhaps most importantly, we need to understand why patients are considering surgery now. A tool I am using for this purpose is the QIRC, a quality of life questionnaire carefully designed and tested to analyze the benefits patients both expect and receive from Lasik surgery. Research done using the QIRC demonstrates that patients considering Lasik are significantly more troubled by their glasses or contact lenses than normal patients. Perhaps even more meaningful, with very few exceptions these same patients enjoyed a large improvement in quality of life after surgery beyond the levels of those who continued in glasses or contact lenses. Although it takes a few extra minutes to complete and analyze, tools like the QIRC allow us to better discuss risk/benefit decisions with our patients.
“Time is money”
Finally, I would hope it is now obvious why Lasik surgery pricing varies so much in our community and in the US in general, even when everyone claims to use the “best” equipment. Adequate screening, counseling, and examination before and after surgery is time intensive even though the surgery itself is brief. This is money well spent. Amongst experts in the field, there is nearly universal agreement that the surgeon is responsible for taking the time to personally perform the preoperative evaluation and counseling as well as providing post-operative care until the patient is stable. In reality, this is far from the case in a surprising number of clinics. At EyeHealth Northwest we provide direct unlimited access to our surgeons for each Lasik patient. With 10 Lasik surgeons on staff, 24/7 coverage with access to multiple specialists is ensured if needed.
“Expert opinion requires an expert”
In conclusion, hopefully it is now clear that a detailed personal consultation with your surgeon is in your best interest whether you are an “excellent” candidate for surgery or not. If you are not an “excellent” candidate, then it becomes critical to receive the best quality consultation from an Ophthalmologist with broad surgical and medical experience to learn about the numerous options available, and together make the best decision for your eyes.
